A few weeks ago I was asked to meet "Annabelle" in the reception area - turned out to be a young man, who said "just call me Annie." His name was really Anibel or Ani, a name that is apparently not uncommon for Cuban males.
Also, here are 2 more examples of females using nicknames usually associated with males: the Canadian author and journalist Stevie Cameron is a woman - I wonder if this is short for Stephanie. And I know a Jeff, originally a Jennifer.
Helen, that IS interesting about the "sister" surnames, never heard that before.